Method of producing a protective coating, protective coating, and component with a protective coating

ABSTRACT

A method for producing a wear-resistant, temperature-resistant, and corrosion-resistant protective coating for a component, in particular for components of a gas turbine, using thermal spraying, wherein during the application onto the component of the protective coating, which consists of a hard material-metal combination, in order to produce an abrasive surface a structuring of that surface of the protective coating that faces away from the component takes place, the hard material or materials consisting of boron nitride particles, titanium carbide particles, tungsten carbide particles, chromium carbide particles, and zirconium oxide particles, or a mixture thereof, and the hard materials having a particle size of 0.1 μm-200 μm, and the protective coating having a thickness of 10 μm-6.0 mm.

The present invention relates to a method for producing a wear-resistant, temperature-resistant, and corrosion-resistant protective coating or layer for a component, in particular for components of a gas turbine, using thermal spraying. In addition, the present invention relates to a protective coating, namely a wear-resistant, temperature-resistant, and corrosion-resistant protective coating for a component, in particular for components of a gas turbine, having an abrasive surface. In addition, the present invention relates to a component, in particular a component of a gas turbine, having a protective coating.

Such coatings for protecting against corrosion and against oxidation are known, and are used in particular in parts of turbines or aircraft engines, and also combustion chambers. What are known as MCrAlY coatings are used as heat corrosion protective coatings, as described for example in U.S. Pat. No. 4,080,486, EP-B1-0486489, and U.S. Pat. No. 4,585,481. In addition, these MCrAlY coatings may be used as bonding agents or as an adhesive layer between the metallic substrate onto which the protective coating is applied and a ceramic covering layer. The application of the protective coating takes place in particular using thermal spraying methods, such as e.g. flame spraying, high-speed flame spraying, detonation spraying, plasma spraying, electric arc spraying, laser spraying, or melt-bath spraying. From DE-A1-10260462 and DE-A1-10351168, additional methods are known for producing a wear-free layer using thermal spraying. U.S. Pat. No. 5,935,407 also describes the application of a MCrAlY base layer onto a workpiece using a plasma spraying method.

A disadvantage of these known methods, and of the protective coatings that result from them, is that in order to produce known protective coatings having abrasive surfaces or properties, it is always necessary to use a plurality of method steps to apply the actual protective coating. In addition, the protective coatings resulting therefrom always have a multilayer construction (see also EP-A1-0443877). Because of the high time expense involved in a corresponding coating of a workpiece and the material outlay connected therewith, this results in relatively high manufacturing costs. In addition, required repairs of damaged protective coatings are also very time-intensive and expensive to perform.

Therefore, the object of the present invention is to provide a method of the type named above that on the one hand can be carried out economically and on the other hand permits a simple and rapid coating of corresponding components.

In addition, the object of the present invention is to provide a protective coating of the type named above that can be manufactured simply and with a low material outlay and that has abrasive properties.

The object of the present invention is also to provide a component of the type named above that is at least partly coated with a protective coating that is simple and that can be applied economically.

These objects are achieved by a method, a protective coating, and a component according to the features and method steps described in independent Claims 1, 5, and 16.

Advantageous constructions are described in the subclaims.

In a method according to the present invention, a wear-resistant, temperature-resistant, and corrosion-resistant protective coating is applied to a component, in particular a component of a gas turbine, by thermal spraying, the protective coating, which consists of ceramic and/or of a hard material-metal combination, being applied onto the component in order to produce an abrasive surface of a structuring of the surface of the protective coating facing away from the component. In this way, it is advantageously possible for the wear-resistant layer to be applied in a single working step, i.e. in one layer, using thermal spraying. The structuring of the surface of the protective coating facing away from the component takes place simultaneously. Because no additional work steps are required to produce the protective coating, the method can be carried out economically, simply, and rapidly.

In an advantageous construction of the method according to the present invention, the structuring is produced by a covering masking during the application of the protective coating. However, it is also possible for the structuring to be produced by a segmented application of the protective coating, or of individual protective coating elements. In addition, is possible for the structuring to be produced by an application of the protective coating onto the component having different thicknesses. Advantageously, the type of structuring can be predetermined and adapted to the corresponding requirements of the component or of the protective coating.

A protective coating according to the present invention, namely a wear-resistant, temperature-resistant, corrosion-resistant protective coating for a component, in particular for components of a gas turbine, has an abrasive surface, the protective coating having a one-layer construction and being applied onto the corresponding component by thermal spraying, a structuring of the surface of the protective coating facing away from the component taking place during the application of the protective coating, which is made of ceramic and/or a hard material-metal combination, in order to produce the abrasive surface. Such a protective coating can be produced simply and economically. In particular, repairs to damaged protective coatings can be carried out very quickly.

In an advantageous embodiment of the protective coating according to the present invention, this layer has a thickness of 10 μm-6 mm, in particular 10 μm-300 μm. In addition, the hard material or materials are made up of boron nitride particles, titanium carbide particles, tungsten carbide particles, chromium carbide particles, or zirconium oxide particles, or a mixture thereof. The hard materials can have a particle size of 0.1 μm-200 μm.

In another advantageous embodiment of the present invention, the hard materials are arranged in a matrix made of metal or a metal alloy. Standardly, the metallic matrix is composed according to the formula MCrAlXAE, where M=Fe, Co, Ni, NiCo or CoNi, X=Si, Ta, V, Nb, Pt, Pd, and AE=Y, Ti, Hf, Zr, Yb.

In further advantageous constructions of the protective coating according to the present invention this layer can be fashioned as a continuous or as a segmented layer. In addition, it is possible for the protective coating to have different thicknesses, to be formed with a blade-like shape, or to have a multiplicity of projections on the surface of the layer that faces away from the component. These projections can be for example tooth-like, blade-like, or pointed. The named structuring possibilities of the protective coating according to the present invention are used to form the named abrasive surface.

A component according to the present invention, in particular a component of a gas turbine, in particular a blade, has in at least one partial area, in particular the blade tip, a protective coating having the features described above.

The wear-resistant, high-temperature-resistant, oxidation-resistant, and corrosion-resistant protective coating according to the present invention is used in particular for the coating and/or repair of turbine parts and engine parts, in particular of gas turbines in aircraft engines.

Further details, features, and advantages of the present invention result from the exemplary embodiments and examples of use shown in the Figures.

FIG. 1 shows a schematic representation of a first exemplary embodiment of a component according to the present invention having a protective coating according to the present invention;

FIG. 2 shows a schematic representation of a second exemplary embodiment of a component according to the present invention having a protective coating according to the present invention; and

FIGS. 3 a to 3 c show schematically represented side views of further exemplary embodiments of components according to the present invention, each having a protective coating according to the present invention.

FIG. 1 shows a schematic representation of a first exemplary embodiment of a component 10 having a protective coating 12. The depicted component 10 is a turbine blade 20 having a blade foot 22 and a blade tip 18 situated opposite blade foot 22. It can be seen that protective coating 12 is fashioned on blade tip 18. Here, protective coating 12 is intended to be wear-resistant, temperature-resistant, and corrosion-resistant, and is standardly called a blade tip armor. In order to produce an abrasive surface or abrasive properties, protective coating 12 is fashioned so as to be structured on the surface of the layer that faces away from component 10. The structuring takes place during the application of protective coating 12 onto component 10. In the depicted exemplary embodiment, protective coating 12 has a multiplicity of projections 16 on surface 14 that faces away from component 10.

FIG. 2 shows a schematic representation of a second exemplary embodiment of a component 10 having a protective coating 12. In this exemplary embodiment, component 10 is also a turbine blade 20. It can be seen that in this exemplary embodiment, protective coating 12 is fashioned as a continuous layer. Abrasive properties of protective coating 12 are achieved in this exemplary embodiment through different thicknesses of protective coating 12, or also through a blade-like design of protective coating 12 (cf. FIG. 3 c).

FIGS. 3 a to 3 c show schematic side views of additional exemplary embodiments of components 10, each having a protective coating 12. These components 10 are, again, turbine blades 20. It can be seen that each of the blade tips 18 is covered at least partly with protective coating 12. Protective coating 12 shown in FIG. 3 a has a segmented construction (cf. also FIG. 1). The protective coatings 12 shown in FIGS. 3 b and 3 c have cross-sections that taper outwardly. This results in cutting edges 24 that create the abrasive property of protective coating 12 on surface 14 situated opposite component 10. 

1-13. (canceled)
 14. A method for producing a wear-resistant, temperature-resistant, and corrosion-resistant protective coating for a component, in particular for components of a gas turbine, using thermal spraying, characterized in that during the application onto the component of the protective coating, which consists of a hard material-metal combination, in order to produce an abrasive surface a structuring of that surface of the protective coating that faces away from the component takes place, the hard material or materials consisting of boron nitride particles, titanium carbide particles, tungsten carbide particles, chromium carbide particles, and zirconium oxide particles, or a mixture thereof, and the hard materials having a particle size of 0.1 μm-200 μm, and the protective coating having a thickness of 10 μm-6.0 mm.
 15. The method as recited in claim 14, wherein the structuring is produced by a covering masking during the application of the protective coating.
 16. The method as recited in claim 14, wherein the structuring is produced by a segmented application of the protective coating.
 17. The method as recited in claim 14, wherein the structuring is produced by applying the protective coating onto the component with different thicknesses.
 18. A protective coating, namely a wear-resistant, temperature-resistant, and corrosion-resistant protective coating for a component, in particular for components of a gas turbine, having an abrasive surface, wherein the protective coating has a one-layer construction and is produced using a method according to claim 14, and that the protective coating is made of a hard material-metal combination, and that the hard material or materials consist of boron nitride particles, titanium carbide particles, tungsten carbide particles, chromium carbide particles, and zirconium oxide particles, or a mixture thereof, and that the hard materials have a particle size of 0.1 μm-200 μm, and that the protective coating has a thickness of 10 μm-6.0 mm.
 19. The protective coating as recited in claim 18, wherein the protective coating has a thickness of 30 μm-300 μm, in particular 30-150 μm.
 20. The protective coating as recited in claim 18, wherein the hard materials are situated in a matrix made of metal or a metal alloy.
 21. The protective coating as recited in claim 14, wherein the protective coating is fashioned as a continuous or segmented layer.
 22. The protective coating as recited in claim 14, wherein the protective coating has different thicknesses.
 23. The protective coating as recited in claim 14, wherein the protective coating has a blade-like construction.
 24. The protective coating as recited in claim 14, wherein the protective coating has a multiplicity of projections on the surface of the layer that faces away from the component.
 25. A component, in particular a component of a gas turbine, having a protective coating as recited in claim
 18. 26. The use of a wear-resistant, temperature-resistant, oxidation-resistant, and corrosion-resistant protective coating as recited in claim 18, for the coating and/or repair of turbine parts and engine parts, in particular of gas turbines in an aircraft engine. 